How to Water Plants Effectively

Level: Beginner

You don’t have to be an expert gardener to know that plants require water to thrive and survive. But how do you know if you’re giving them too much or too little water, or even watering your plants properly? Different types of plants, whether grass, trees, flowers, potted plants or garden vegetables, require specific amounts of water. Keep reading for tips on how to give your plants the exact amount of water they need.

Water Your Lawn

Every homeowner wants a lush, green lawn. In the summer heat, this requires regular deep watering. Consistent watering prevents the root structure of the grass from rising toward the surface in a desperate search for water, which makes the roots vulnerable and can harm or even kill the grass. At the same time, you don’t want to overwater. Standing water, combined with humidity, leads to fungus growth.

As a general rule, most lawns require about 1" of water, once a week from rain or irrigation to penetrate down to the roots. This can usually be achieved by using a garden sprinkler, the most convenient and efficient method of watering a lawn. The length of watering time will vary, depending on how you irrigate your lawn. For example, different types of sprinklers saturate the ground slower or faster than others. Just remember that shorter, more frequent watering can produce a shallow root system which makes the grass more vulnerable to weeds and insects.

There are many sprinkler types, qualities and prices to navigate. A portable lawn sprinkler provides slow overhead watering for deep penetration, but it is important to select a sprinkler that fits the size and shape of your garden to avoid wasting water on the sidewalk through evaporation. Ask an expert at your local True Value hardware store for help deciding what’s best for your yard. Your sprinkler’s watering rate should be set to about 1/2" per hour. Anything faster will cause runoff in most soils. To determine just how much water your sprinkler is putting out per hour, use three empty tin cans (such as tuna cans) that are of identical size. Place them at different distances from the sprinkler, within the sprinkler pattern. Turn on the water for an hour, and then empty all water into one of the cans. Using a ruler, measure the depth of the water and divide by three. This gives the amount of water your sprinkler supplies the lawn in an hour.

Helpful Tips

Water grass only when necessary; watch the weather to see if you’ll be getting any rain, and how much, during the week. You don’t need to water if the rain will do it naturally.

Here is a simple test to perform to determine if your grass needs watering: Walk on the grass. If you leave footprints, it needs watering. Moist grass springs right back, but dry grass doesn’t.

Grass turns a silvery blue in areas and, if not watered soon, will turn brown when it isn’t getting enough water.

Try to water in the morning, rather than the afternoon or evenings. Watering in the morning when the sun is low and it's cooler allows for better water intake. The afternoon sun can dry up the water before it has time to soak into the ground to the roots. Evening watering sometimes can be problematic, as it can encourage the spread of fungus and disease from the overly wet conditions.

Water Trees

Though trees are much more resilient than flowers or grass, you still need to pay attention to how much water they're getting, especially as hot weather hits. One thing to keep in mind: Trees get much of their water from their massive network of fine roots, which quickly get saturated when water is available. So, just spraying a ton of water at the tree's base with a garden hose doesn't cut it because the root system isn't absorbing it there. Most of the water will run off and not sink down deep into the roots. Instead, spray where the tree's feeder roots are actively growing. These are the young tips at the outer edges of the root system that are actively taking up water and nutrients. They can be found at the outer edges of the tree's drip line. The drip line is an imaginary line drawn from the canopy edge to the ground, where water would drip off the tree if it rained. You can also use a soaker hose to supply a slow, steady dosage at the drip line to maximize the tree roots’ water intake. A soaker or trickle hose is a perforated hose that you can wrap in a circular area around the tree's root zone. Water trickles out of the network of holes in the hose to water the ground around it.

Newly planted trees and shrubs need a minimum of 1" of water per week. Since a tree’s roots can extend 3' or more below the ground, they should be watered with enough water so that it reaches that depth. For established trees, you can tell if they need water if the branches start to droop or the leaves wilt or curl and don’t recover overnight, or if you've had less than an inch of rain in a few weeks. During a drought, water deeply once or twice a week until the drought ends.

Water Flowers and Potted Plants

Watering flowerbeds requires a delicate approach, especially if you use a garden hose with a sprayer nozzle to water your plants. A low-powered setting, such as mist or shower, should be used if you apply this method of watering. This mild setting prevents damage to petals and blooms from forceful blasts of water. Wand sprayer attachments are specially designed for easy watering of flowerbeds and gardens.

Using a sprayer though can be problematic, according to many experts. Depending on the plant type and the climate conditions in your region, this overhead style of watering can sometimes leave the plants’ above-ground vegetation too damp, which may lead to plant disease, if plants are particularly susceptible to these kinds of problems. Since you’re actually aiming to water the plants’ roots, soaker hoses or other drip irrigation systems are very effective at ensuring your flowers get the water they need. Most root systems of flowering plants are about 1' below ground, so it’s best to water the soil so that water reaches that depth.

For inexpensive but effective drip irrigation, punch holes in the bottoms of large juice or coffee cans with a hammer and nail. Push the cans 6" to 12" into the soil (right side up) and fill them with water. The water will gradually seep from the bottom into the soil directly surrounding the roots. This method will greatly reduce evaporation and unnecessary wetting of surrounding soil.

Helpful Tips

Use a soil probe to determine the amount of moisture in your soil. These probes are pointed pieces of metal that you push into the soil. It will move fairly easily through moist soil and stop when it hits hard, dry soil. This way you can see how far down the water is being absorbed.

You can also use a digital soil moisture meter to determine how much water is in your soil.

No matter how you deliver water to your plants, for best results, it’s ideal to water flowers in the morning. This allows time for the water to seep into the soil before it gets evaporated by the sun and allows the foliage to dry quickly (if you spray your flowers with water), which prevents potential fungal diseases.

You should water your plants occasionally and deeply instead of many times lightly. The water should be allowed time to soak in to be absorbed by the deep roots.

Helpful Tips

Watch for wilting flowers or dry, hardened soil. These are good signs that plants need water.

Add a layer of mulch to keep roots cool and prevent plants from drying out. Use organic mulch, such as shredded bark, grass clippings, or shredded leaves. Apply the most mulch around the drip line of the plant, which is the area below the furthest branches. Don’t pack it up against the trunk or cover the crown.

Grow plants with low water needs; not all plants require constant watering. Perennials such as mums or trilliums require less water than annual bedding plants, due to their self-maintaining properties. Colorful native plants are a great choice as well.

For indoor plants, the trusty watering can is your best weapon. It's easy to over-water or under-water potted plants. It’s also common to water all plants with the same amount of water as the others, but over-watering is a common cause of killing plants, just as under-watering can be. Too much water makes the soil too wet and can cause root rot and disease. If you under-water your plants, then your plants will not get the nutrients they need from the water or the soil. So be sure to understand the watering needs of each individual houseplant to ensure it receives the proper hydration. To water your plants, simply add water until it drains out of the bottom of the pot (this helps remove any excess minerals, salt or fertilizer). Don't water the plant again until the soil is nearly dried out (just check to see how dry it is with a finger every couple of days). Try to water your plants in the morning.

Helpful Tips

Distilled water is much better for your plants than tap water, which contains chemicals like salt and chlorine. If you must use tap water, put it in a container and let it stand for about two days before adding it to your plants. You can also use rainwater. To gather rainwater, set a pan outdoors during the next downpour.

Don't put plants in pots without holes in the bottom.

Water Vegetable Gardens

Vegetable gardens can be watered much like any of the other plants mentioned above. Possibly, the most efficient way to water is with a soaker hose, which produces a slow stream of water directly to the soil. Using a sprinkler doesn’t make as much sense for watering a garden plot, as they can waste a lot of water. A light, direct misting from a garden hose or even a watering can, depending on the size of your garden, are also good choices. A soaker hose delivers water where it's needed — at the roots of the plant. This method usually allows the foliage to stay dry, which helps keep diseases to a minimum.

If you use soaker hoses, leave them on for about an hour. Then use a soil probe to check how much water has been delivered. Eventually, you'll learn how long you need to keep the hoses on to water your garden plants deeply. Different plants have different watering needs, so understand how much each of your vegetable plants requires. Most garden plants require that you only water the top 8" to 12" of soil. Some plants though, such as tomatoes, have roots that can grow sometimes to 2' below ground. These plants will require deeper watering.

Helpful Tips

Use more than one soaker hose to irrigate your garden if you have multiple rows.

Watering deeply once a week conserves water and is more beneficial than lightly watering multiple times a week.

Water early in the morning to minimize evaporation.

Use timers on sprinklers and soaker hoses throughout your garden.

Good job! Water your plants the way they want to be watered and watch them grow.

Related Posts & Videos

Here’s what you’ll need to complete this project successfully.

Before you begin, use the shopping list below to uncheck the tools you already have to complete this project.

Then, print or save your updated list and bring it to your local True Value hardware store, where an expert Hardwarian will give you the remaining tools and expert advice you need to complete this project.

You can also shop online for these project items at TrueValue.com and receive FREE shipping to a participating store.

Open a Store

If you're interested in being your own boss, True Value offers opportunities to develop a successful business. As a True Value retailer, you can run your business your way. True Value Company is a retailer‑owned co‑op.